The HfC-coated Si field emitter arrays (FEAs) controlled by built-in poly-Si thin-film transistors (TFTs) were fabricated. The FEAs were fabricated at a relatively low temperature using Ar-ion-sputter sharpening so that a low-temperature poly-Si TFT process can be applied. A HfC thin film was coated on emitting tips for improving emission lifetime. An emission control TFT having a conventional top-gate structure was fabricated using ion implantation and activation annealing. A combination of multigate and lightly doped drain (LDD) structures was effective at reducing leakage current at a high source-drain voltage. We fabricated a HfC FEA integrated with a TFT having four gate electrodes with a LDD structure. Complete control of FEA emission current by built-in TFT was demonstrated in a vacuum chamber. The detailed fabrication process and emission control characteristics are reported. (c) 2006 American Vacuum Society.